Abstract

Intense, pulsed beams of low‐energy positrons have been produced by a high‐energy beam from an electron linac. The production mechanism has been studied near 100‐MeV incident energy and several characteristics that affect slow‐positron production have been identified. These characteristics include the geometry of the electron‐positron converter and positron moderator, the thickness of the converter, and the energy of the electron beam. The production efficiency for producing low‐energy positrons has been determined experimentally. The results imply that low‐energy positron beams from a linac can be of much higher intensity than those beams currently derived from radioactive sources.